Soft tissue sarcomas are a group of cancers that come from the fat, muscles, blood vessels or nerves of your body. Sarcomas form when normal cells in these tissues change and become cancerous. Sarcomas that start in the bone are different from soft tissue sarcomas and are not reviewed here. Unlike some other cancers, the cause of most sarcomas is unknown. Exposure to cigarette smoke, alcohol and diet have not been associated with any sarcomas.
According to the American Cancer Society, there will be 13,520 new cases of sarcoma in 2025. Sarcomas are very rare, making up less than 1% of new cancers. Adults and children can develop a sarcoma, but it is most common in adults.